[en] The Convention on Early Notification of a Nuclear Accident (the 'Early Notification Convention') and the Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (the 'Assistance Convention') are the prime legal instruments that establish an international framework to facilitate the exchange of information and the prompt provision of assistance in the event of a nuclear accident or radiological emergency, with the aim of minimizing the consequences. The International Atomic Energy Agency (IAEA) has specific functions assigned to it under these Conventions, to which the World Health Organization (WHO), the World Meteorological Organization (WMO) and the Food and Agriculture Organization of the United Nations (FAO) are full parties. Since 1989, the arrangements between the IAEA, States which are IAEA Member States and/or Parties to one or both Conventions, all other relevant international intergovernmental organizations, and other States for facilitating the implementation of the Conventions - specifically of those of their articles which are operational in nature have been documented in the Emergency Notification and Assistance Technical Operations Manual (ENATOM). Recent events, for example, the launch of the Cassini satellite (USA, 1997), the Acerinox accident (Spain, 1998), the JCO criticality accident (Japan, 1999), the Istanbul accident (Turkey, 1999) and the Samut Prakarn accident (Thailand, 2000), have raised new issues and highlighted the expectation of States that the IAEA will use the framework of the Early Notification and Assistance Conventions to obtain and provide real-time emergency related information on such events. While the Early Notification Convention requires States Parties to report only accidents that may have significant transboundary radiological consequences, States may under the Assistance Convention legitimately request the assistance of the IAEA or an Accident State in obtaining information concerning a nuclear accident or radiological emergency even if there is no direct transboundary impact, primarily for the purposes of minimizing the consequences of the accident or emergency e.g. for trade and tourism and providing advice to their nationals living, working and travelling in the Accident State. The provision of such information would also help to avoid unnecessary international rumours and concerns. In order to be able to provide such information in an emergency, States need to be prepared in advance. Moreover, States are encouraged to provide warning messages and other relevant information within the ENATOM framework even in the event of a nuclear accident or radiological emergency that does not trigger the Early Notification Convention but is of international concern. Recent work on clarifying emergency classification schemes for nuclear facilities and on identifying the key information to be transmitted for technical assessment purposes, the development of emergency preparedness and response standards and improvements in communications technology (e-mail and Web servers) have been reflected in the arrangements described in this new edition of ENATOM. ENATOM addresses the issue of requesting and providing assistance in the event of a nuclear accident or radiological emergency. For the provision of assistance, the IAEA is establishing a global Emergency Response Network (ERNET) of teams suitably qualified to respond rapidly, on a regional basis, to nuclear accidents or radiological emergencies. ENATOM states the Secretariat's expectations rather than prescribing arrangements. Nevertheless, all States, including States which are neither Member States of the IAEA nor party to either Convention, and the relevant International Intergovernmental Organisations are invited to adopt the arrangements described in it for providing and receiving information about nuclear accidents and radiological emergencies. In the event of a nuclear accident or radiological emergency, the prompt provision of information and assistance can be an important element for helping to mitigate the consequences. ENATOM will be reissued every two years. Any important amendments between editions will be made through Information Bulletins. This edition will enter into effect on 1 December 2000, before which the detailed procedures and checklists at the IAEA Headquarters will be updated and tested